UNTIL recently, there had been no beavers anywhere in the United Kingdom for four hundred years. Beavers were prized for their valuable pelts, so much so that Britain and France colonised North America simply to take control of the fur trade. Beavers were already rare in Great Britain in the Middle Ages, but the very last British beaver was shot in Scotland in 1526, against the backdrop of that relentless quest for profit.
Humans have been reshaping Britain’s environment for thousands of years. Our familiar patchwork quilt of farms and copses is entirely artificial, and you’d only have to go back a thousand years to discover a wild, thickly-forested landscape populated by long-disappeared animals like wolves and wild boar. The beaver is only one of our many casualties, and its extinction on Great Britain came alongside the destruction of many unique habitats, such as the fens.
And the damage continues: we’ve learned that around 56% of Britain’s species have declined over the last four decades, with 15% of them threatened by extinction. Insect and bird populations have been hardest hit, although the humble British hedgehog has declined by a devastating 97%.
But there is good news: the beaver is back. Small populations have slowly been released into the wild, starting in Kent in 2001, and most recently in the Forest of Dean last summer. Reintroducing a vanished species into an environment in which it once flourished is called rewilding.
Rewilding differs from normal conservation efforts because it seeks not just to bolster a declining population, but to totally transform an entire ecosystem in the process. It’s a vital step towards restoring out shattered national ecosystem. Beavers are the standard-bearers, however, because the consequences of their reintroduction on the environment are so enormous.
Beavers transform the landscape. They carve out channels, fell trees and build dams; the trees they destroy are replaced by wild undergrowth and the dammed rivers saturate the surroundings, creating new wetlands and shaping new habitats in which unfamiliar creatures can populate and thrive. Their dams even have a positive impact for humans, because they control the flow of water, thereby preventing flooding further downstream – this is at least one of the motives for their reintroduction into the flood-prone Forest of Dean.
Beavers are known as ‘ecosystem engineers’, because the transformative effect their dams have are impossible for humans to replicate. River and wetland habitats thrive when beavers are present, and in Britain this means amphibian, insect and bird populations will flourish alongside them.
Although their dams are a particularly visible example, beavers are not the only eco-system engineers. Other species have a no less dramatic impact simply via the niche they fill within a delicate ecosystem.
For instance, reintroducing wolves to Yellowstone National Park in 1995 helped to control the ballooning elk population, which reduced pressure on plants, thereby facilitating new growth and allowing birds and beavers to thrive, which in turn meant tree cover increased, which meant the soil became less saturated, which changed the course of rivers and transformed the very shape of the landscape. Yellowstone’s riverine ecosystem recovered dramatically in the space of a few years.
Rewilding has already been successful in the UK, with Golden Eagles and Red Kites brought back from the brink of extinction.
The evidence in favour of rewilding was incontrovertible. There are even plans to attempt something similar in the UK, recreating the ancient wolf and lynx populations in the hope of culling deer and restoring the environment to something resembling a more ‘natural’ state.
Wolves are what’s called a ‘keystone predator’, because the impact on the environment they have is far larger than the relative size of the wolf population. As the ecosystem’s apex predator, any change in its density has a cascading effect on the rest of the environment – the original elimination of wolves from Yellowstone, for example, allowed the elk population to run amok, overgrazing the woodland and encroaching on the habitat of other herbivores.
Rewilding schemes have already been successful in the UK, with Golden Eagles and Red Kites brought back from the brink of extinction over the last few decades, and populations of wild boar (not seen in Britain since the middle ages) beginning to thrive in our woodlands. Boar are a particularly important ecosystem engineer, as their constant snuffling and digging on the forest floor uproots seeds and encourages new growth.
It’s all very lovely and positive – and yet, predictably controversial.
Farmers, Britain’s most entitled demographic, are the most vocal critics of rewilding. They’re needlessly frightened of potential new predators (public outcry led to the abandonment of an attempt to reintroduce white-tailed eagles to East Anglia), and suspicious of herbivores like wild boar, which they are allowed to kill indiscriminately. Furthermore, many farmers protest the loss of productive, food-producing farmland to wilderness, despite the horrendous environmental damage demonstrably done by overfarming.
There are, I think, lessons to be learned from beavers. Humans have destroyed so much of Britain’s natural diversity, felling forests, slaughtering wild animals, draining wetlands and poisoning waterways. The environmental campaigner George Monbiot put together a list of 15 animals we could reintroduce to Britain, some thousands of years after we killed the last native individual.
But rewilding shows we can make amends. It demonstrates the paths we can take to restore the environment, to return the landscape to its natural state and give animals that once thrived on these shores another chance. And as we stare down the barrel of climate catastrophe, it also gives us hope that we can undo the terrible damage we’re doing to the planet, that the crisis already unfolding can be halted, or even reversed. Rewilding is gaining pace all over Europe, and if there’s one thing we can learn from the beaver, it’s that something small and simple like releasing a few tiny mammals into the wild can have a unexpected impact.